An earthquake measuring 4.1 on the Richter scale jolted Zigui County in central China's Hubei Province at 4:01 p.m. Saturday, Xinhua quoted the National Seismic Network as reporting. The epicenter, located at 31 degrees north latitude and 110.8 degrees east longitude, is about 30 kilometers from the Three Gorges Dam, a leading water conservancy project on the Yangtze River, China's longest waterway. "We assume the epicenter is along the banks of the Xiangxi River, a Yangtze tributary in the dam area," said Zheng Zhiwen, a spokesman with the county committee of the Communist Party of China (CPC). Zheng said the local government had sent teams to investigate potential damages in the area. No casualties have been reported as yet. The tremor had not affected the dam itself, said a spokesman with Three Gorges Project Corporation. "The dam was built to endure far stronger earthquakes," he said. Launched in 1993, construction of the gigantic concrete structure of the Three Gorges dam was completed and began to hold water in May 2006. The dam was unaffected in the 8.0-magnitude earthquake that hit Sichuan Province on May 12.